Hydraulic tube bending machine



Oct. 4,' 1966 J. H. STANLEY HYDRAULIC TUBE BENDING MACHINE 5 Sheets-Sheet 1 Filed July 2, 1963 INVENTOR JoHu H. $TAMLEY Oct. 4, 1966 J. H. STANLEY HYDRAULIC TUBE BENDING MACHINE 5 Sheets-Sheet 2 Filed July 2, 1963 R Y m E E H a d O w A win .I. my m u. u \m H O 7 J ,TMM, m

k ARN v WQ t S P1 A m nd n ww K Oct. 4, 1966 J. H. STANLEY 3,276,235

HYDRAULIC TUBE BENDING MACHINE Filed July 2, 1963 3 Sheets-Sheet 5 FIG I NVENTOR JOHN H. STANLEY United States Patent 3,276,235 HYDRAULIC TUBE BENDING MACHINE John H. Stanley, Euclid, Ohio, assignor to Parker-Hannifin Corporation, Cleveland, Ohio, a corporation of Ohio Filed July 2, 1963, Ser. No. 292,284 15 Claims. (Cl. 72149) This invention relates to a hydraulic tube bending machine and more particularly to a novel arrangement of parts for applying motion to the tube bending devices and novel adjustable stop mechanism for determining the angle to which the tube is to be bent.

It is old and well known in the tube bending art to bend a tube to a desired angle by providing a radius block which is drivingly connected to a sprocket having a link type chain trained thereabout and each end of the chain connected to separate fluid operated motors. In such a device, it is necessary to provide a plurality of control devices for shutting off the fluid and stopping the fluid motors when the tube has been bent to a desired angle. Such control mechanisms have heretofore included a plurality of relatively expensive valve mechanisms for directing operating fluid selectively to the fluid motors wherein one fluid motor provides the necessary force for bending the tube and the other fluid motor retracts the mechanism to a starting position. fluid motors necessarily complicates the valve mechanism and requires means for shifting the valve mechanism so as to shut off the operating fluid when the radius block has turned through a predetermined desired angle and for shutting off the fluid when the radius block has been returned to its initial set position.

It is an object of this invention to provide a hydraulic tube bending machine which includes only one singleacting fluid motor for actuating a chain drive and thereby avoiding the use of complicated and expensive valving arrangements.

Another objectof this invention is to provide a tube bending machine having a radius block, a sprocket connected to the radius block in driving connection therewith, fluid motor means for rotating the radius block, a chain engaged with the sprocket, one end of the chain being connected to the fluid motor means and the other end of the chain being connected to an adjustable stop mechanism for limiting the movement of the chain, wherein the stop mechanism includes a rod and a block, means for adjustably positioning the block along the rod, and a stop collar connected to the chain and being movable thereby into engagement with the block to prevent further movement of the chain.

Another object of this invention is to provide the above described bending machine with a bend-angle indicator scale which is disposed adjacent to the block and has indicia thereon, the block being provided with means for cooperating with the indicia to indicate the position of the block.

Another object of this invention is to provide a tube bending machine of the character stated with a clamp block which is carried by the radius block for clamping thereto a tube which is to be bent, a vise block, a slider block mounted in the vise block for sliding movement with the tube, and means for adjustably positioning the vise block.

Another object of this invention is to provide a tube bending machine of the character stated with a guide tube, a fixed block attached to one end of the guide tube, a portion of the chain being disposed within the guide tube and being connected to a guide pin, slot means in the guide tube, the guide pin being slidably mounted in the slot means to maintain the chain in cooperative alignment with the sprocket, a journal block supporting the The use of a pair of other end of the guide tube, and spring means disposed between the fixed block and the guide pin to bias the guide pin toward the journal block.

Another object of this invention is to provide an adjustable stop mechanism for a drive means wherein the stop mechanism comprises a rod and a traveling block,

justable stop mechanism of the character stated with a transparent cover to retain lubricant, to exclude dirt and to protect the indicator scale.

Another object of this invention is to provide an adjustable stop means of the character stated wherein the previously mentioned rod is a threaded screw which is mounted for rotation and held against translation by the journal block, a stop collar connected to the chain and movable with respect to the screw threaded rod, and a threaded traveling block which is mounted for translation along the rotatable screw threaded rod between the journal block and the stop collar.

A further object of this invention is to enclose the stop mechanism within a housing which has a slot formed therein above the screw threaded rod, and to provide the screw threaded traveling block with a pointer which is disposed within the slot to prevent rotation of the traveling block and also cooperates with the indicia on the indicator scale for determining the position of the traveling block.

A still further object of this invention is to provide a stop mechanism of the character stated wherein the stop collar is connected to one end of the chain by a pair of flat links and a guide pin, and includes a guide tube which encloses a portion of the chain and has slot means therein for slidably receiving the guide pin and thereby preventing twisting of the chain.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the folowing detailed description, the appended claimed subject matter and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a plan view of a portable hydraulic tube bender, which encompasses the present invention, and shows a radius block being disposed in engagement with a tube prior to a bending operation, a clamp for clamping the tube to the radius block, a slider block and vise means for engaging the tube, a chain drive for rotating the radius block and an adjustable stop mechanism for limiting the travel of the drive means.

FIGURE 2 is a longitudinal elevational view, with parts broken away for clarity, and shows one end of a link chain being connected to a vertically disposed guide pin which travels in a slotted guide tube and is spring biased toward a prebending position by a helical spring which is concentric with the guide tube, and also shows the guide pin as being connected by a pair of flat links to a stop collar, which collar is in engagement with a traveling block that is threadably mounted on a stationary screw rod and thereby prevents movement of the link chain.

FIGURE 3 is a horizontal longitudinal sectional view, taken on line 33 of FIGURE 2, and shows the link chain as being connected at one end to an adjustable stop mechanism, a central portion of the link chain be-,

Patented Oct. 4, 1966 ing trained around a drive sprocket and the other end of the link chain being connected to a piston rod of a pivotally mounted fluid motor.

FIGURE 4 is an enlarged vertical longitudinal se-ctional view, taken on line 4-4 of FIGURE 1, and illustrates the details of the adjustable stop mechanism.

FIGURE 5 is an enlarged vertical transverse crosssectional view, taken on line 55 of FIGURE 2, and shows the guide tube as being firmly held within a split block.

FIGURE '6 is an enlarged sectional view, taken on line 66 of FIGURE 2, and shows the guide pin as being received within a pair of vertically aligned slots in the guide tube.

FIGURE 7 is a fragmentary vertical cross-sectional view, taken on line 7--7 of FIGURE 4, and shows a pair of vertically aligned flat links disposed within recesses in a fixed journal block.

FIGURE 8 is a fragmentary vertical cross-sectional view, taken on line 8-8 of FIGURE 4, and shows a threaded traveling block mounted on the screw threaded rod and having a pointer which is disposed for travel within a slot in the housing to prevent rotation of the threaded traveling block.

Referring to the drawings in detail, there is shown a portable tube bending machine, generally indicated by the numeral 10, which includes a housing 11 and a plurality of lugs 12 for fixing the tube bending machine to a work surface, not shown. A rod or tube 13, which is to be bent, is disposed transversely of the tube bending machine 10 and is engaged on opposite sides by a radius block 14 and a slider block 15.

The slider block 15 is provided with a plurality of arcuate cut-outs 16 for receiving therein various sizes of tubes 13 and is mounted for sliding movement with the tube 13, as the tube moves during bending, by a vise block 17. The vise block 17 is provided with an adjustment screw 18 and a plate 19 for properly positioning the slider block 15. The vise block 17 is mounted for sliding movement on a bed 20 and is movable therealong by a vise screw 21 which is rotatable within a nut block 22 that is welded to the bed 20. A pivotally mounted handle 23 is connected to the vise screw 21 for turning the screw and moving the vise block 17 for pressing the slider block 15 into engagement with the tube 13.

The radius block 14 is provided with the usual U- shaped groove for receiving the rod or tube 13 therein, and as is shown, the radius block 14 is capable of producing a 180 bend in the tube 13. The radius block 14 is mounted for rotation about the axis of a vertically disposed center pin or shaft 24. A rotary plate 25 is keyed to the shaft 24 to turn therewith and carries a drive pin 26 to cause rotation of the radius block 14. The drive pin 26 is received within an opening 27, of the radius block 14, which is offset from the center pin or shaft 24 to provide for a mechanical advantage for turning of the radius block 14. The radius block 14 is provided with a lug 28 which has a threaded bore for receiving a clamp bolt 29 such that the lug 28 cooperates with the clamp block 30 for fixedly clamping the tube 13 to the radius block 14.

The center pin or shaft 24 is rotatably journaled in the housing 11 and is keyed to a sprocket 31. The sprocket 31 has a plurality of teeth 31' for engagement with a link chain 32. One end of the link chain 32 is connected by a pin 33 to a piston rod 34 of a fluid motor, generally indicated by the numeral 35. The fluid motor 35 is preferably hydraulically actuated and includes the piston rod 34, a piston 36 and a cylinder 37 and is provided with hydraulic fluid by a conduit 38 which connects the fluid motor 35 to a pump or other source of pressure (not shown). The cylinder 37 may be welded or rigidly fastened to the housing 11 but as is shown in FIGURE 3, it is preferable to provide a trunnion 39 for pivotally mounting the cylinder 37 to the housing 11 to thereby minimize wear on the piston 36 and the fluid seals (not shown).

The link chain 32 extends from the piston rod 34, is trained about the sprocket 31, and is pivotally secured to a connector rod 41 by a pin 42. As is shown in FIG- URE 5, a split block 43 is securely fastened to the housing 11 by a pair of bolts 44 and is clamped to one end of a guide tube 45 by a locking bolt 46. The guide tube 45 is provided with a pair of longitudinally extending vertically aligned slots 47, as is shown in FIGURES 3 and 6, for slidably receiving therein a guide pin 48 which is carried by the end of the rod 41. A helical return spring 49 surrounds the guide tube 45 and is compressed between the split block 43 and a ring-like abutment member 49 impaled by the guide pin 48 during movement of the piston 36 into the cylinder 37. After completion of a bending operation, the return spring 49 causes the abutment member 49' to slide back along the tube 45 to its position of FIGURES 2 and 4, thus retracting the radius block 14, and returning the piston 36 and the guide pin 48 to the positions shown in FIGURES 1 and 2 in preparation for the next bending operation.

The end of the guide tube 45, opposite from the end thereof which is supported by the split block 43, is supported by a journal block 50. The journal block 50 is rigidly secured to the housing 11 by a plurality of bolts 51, as is shown in FIGURE 7, and has a pair of vertically aligned recesses 52 for slidably receiving a pair of vertically aligned flat links 53 which are connected to the guide pin 48, as shown in FIGURES 3 and 4. The flat links 53 are fixedly connected to a stop collar 54 by a pair of locking bolts 55. The stop collar 54 has a central aperture 56 for receiving therethrough a rotatable, threaded rod or captive screw 57. The rod or screw 57 is rotatably connected to a thrust bearing 59 by a screw 58, said bearing 59 being mounted in the journal block 50, The rod or screw 57 is also journaled for ro tation in the housing 11 as at 58' and is provided with a handle 60. An internally threaded nut or traveling stop block 61 is movable along the rod or screw 57 by rotation of the handle 60.

A pointer 62 travels within a slot 63, in the housing 11, and is connected to the nut or traveling block 61 by a pair of bifurcated legs 64, as is shown in FIGURE 8. A bend angle indicator scale 65 is provided on the housing 11, as is shown in FIGURE 1, and underlies a transparent plastic cover 66 which excludes dirt and protects the indicator scale 65. The bend angle indicator scale 65 is provided with indicia which ranges between zero degrees and and in cooperation with the pointed 62, gives a visual indication of the position of the nut or traveling glock 61 and of the angle to which the tube 13 is to be r ent.

In the operation of the tube bending machine 10, the tube 13 is placed transversely ofthe housing 11 and is clamped to the radius block 14 by the clamp block 30. The slider block 15 is moved into engagement with the tube 13 by advancing the vise block 17 and the vise screw 21 by rotating the handle 23. The nut or traveling block 61 is moved along the rod or screw 57, and away from the stop collar 54, by rotating the handle 60 and the rod or screw 57 until the pointer 62 is positioned along the bend angle indicator scale 65 in alignment with the indicia which indicates the desired bend angle. Fluid under pressure is then provided through the conduit 38 to force the piston 36 and the piston rod 34 into the cylinder 37. Movement of the piston rod 34 into the cylinder 37 causes the link chain 32 to rotate the sprocket 31 and the center pin or shaft 24. The rotary plate 25 is keyed to the center pin or shaft 24, and rotates therewith and moves the drive pin 26 to cause rotation of the radius block 14 and thereby bend the rod or tube 13.

As the chain 32 rotates the sprocket 31, the connecting rod 41 pulls the guide pin 48 along the slots 47 in the guide tube 45 to compress the return spring 49 between the split block 43 and the abutment member 49'. In addition, the guide pin 48 pulls upon the flat links 53 and the block or stop collar 54 until the block or stop collar 54 engages the adjusted nut or traveling block 61 and further movement is prevented thereby. The travel of the guide pin 48 within the slots 47, of the guide tube 45 me vents the chain 32 from becoming twisted and from be coming disengaged from the sprocket 31. Also, as the nut or traveling block 61 is adjusted along the rod or screw 57, the pointer 62 travels within the slot 63 in the housing 11 and prevents the nut or traveling block 61 from rotating about the screw 57.

After the rod or tube 13 has been bent, it may be found that spring-back in the tube has not been accurately compensated for. Thus, it may be necessary to increase the bend by a few more degrees, It is an important feature of the present invention that the rod or screw 57 and the handle 60 do not move axially during the bending operation and, therefore, the handle 60 is always accessible for changing the bend setting without making it necessary for all of the parts to be first returned to their starting positions.

While preferred forms and arrangement of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claimed subject matter.

I claim:

1. In a tube bending machine, a radius block, fluid motor means for rotating said radius block, a sprocket connected to said radius block in driving connection therewith, a chain engaged with said sprocket, one end of said chain being connected to said fluid motor means and the other end of said chain being connected to an adjustable stop mechanism for limiting the movement of said chain, said stop mechanism including a rod and a block, means for adjustably positioning said block along said rod, a stop collar connected to said chain and being movable thereby into engagement with said block to prevent further movement of said chain.

2. In a tube bending machine, a radius block, fluid motor means for rotating said radius block, a sprocket connected to said radius block in driving connection therewith, a chain engaged with said sprocket, one end of said chain being connected to said fluid motor means and the other end of said chain being connected to an adjustable stop mechanism for limiting the movement of said chain, said stop mechanism including a rod and a block, means for adjustably positioning said block along said rod, a stop collar connected to said chain and being movable thereby into engagement with said block to prevent further movement of said chain, a bend-angle indicator scale disposed adjacent to said block and having indicia thereon, said block having means thereon cooperating with said indicia to indicate the position of said block.

3. In a tube bending machine, a housing, a shaft rotatably mounted in said housing and having a sprocket affixed thereto; a fluid motor including a piston disposed therein and a piston rod extending therefrom, a linkchain connected at one end to said piston rod and trained around said sprocket, a radius block disposed above said housing and being mounted on said shaft, a rotary plate keyed to said shaft and carrying a drive pin which cooperates with said radius block to cause rotation thereof, a clamp block carried by said radius block for clamping thereto a tube which is to be bent; at vise block, a slider block mounted in said vise block for sliding movement with said tube, and means for adjustably positioning said vise block.

4. In a tube bending machine, a radius block, fluid motor means for rotating said radius block, a sprocket connected to said radius block in driving connection therewith, a chain engaged with said sprocket, one end of said chain being connected to said fluid motor means and the other end of said chain being connected to an adjustable stop mechanism for limiting the movement of said chain, said stop mechanism including a rod and a block, means for adjustably positioning said block along said rod, a stop collar connected to said chain and being movable thereby into engagement with said block to prevent further movement of said chain; a guide tube, a fixed block attached to one end of said guide tube, a portion of said chain being disposed within said guide tube and being connected to a guide pin, slot means in said guide tube, said guide pin being slidably mounted in said slot means to maintain said chain in cooperative alignment with said sprocket, a journal block supporting the other end of said guide tube, and spring means disposed between said fixed block and said guide pin to bias said guide pin toward said journal block.

5. A tube bending machine comprising, a housing, a shaft rotatably mounted in said housing and having a sprocket aflixed thereto; a fluid motor including a cylinder having a piston disposed therein and a piston rod extending therefrom, a link chain connected at one end to said piston rod and trained around said sprocket, the other end of said link chain being connected to an adjustable stop mechanism for limiting the movement of said link chain; a radius block disposed above said housing and being mounted on said shaft, a rotary plate keyed to said shaft and carrying a drive pin which cooperates with said radius block to cause rotation thereof, a clamp block carried by said radius block for clamping there-to a tube which is to be bent; a vise block, a slider block mounted in said vise block for sliding movement with said tube, and means for adjustably positioning said vise block; said stop mechanism including a rod and a block, means for adjustably positioning said block along said rod, a stop collar connected to said chain and being movable thereby into engagement with said block to prevent further movement of said chain.'

6. A tube bending machine comprising, a housing, a shaft rotatably mounted in said housing and having a sprocket affixed thereto; a fluid motor including a cylinder having a piston disposed therein and a piston rod extending therefrom, a link chain connected at one end to said piston rod and trained around said sprocket, the other end of said link chain being connected to an adjustable stop mechanism for limiting the movement of said link chain; a radius block disposed above said housing and being mounted on said shaft, a rotary plate keyed to said shaft and carrying a drive pin which cooperates with said radius block to cause rotation thereof, a clamp block carried by said radius block for clamping thereto a tube which is to be bent; a vise block, a slider block mounted in said vise block for sliding movement with said tube, and means for adjustably positioning said vise block; a split block fixedly attached to said housing and encompassing one end of a guide tube, said other end of said link chain being disposed within said guide tube and being connected to a guide pin, slot means in said guide tube, said guide pin being slidably mounted in said slot means to maintain said link-chain in cooperative alignment with said sprocket, and a journal block fixed to said housing and supporting the other end of said guide tube; said stop mechanism including a thrust bearing carried by said journal block, a rotatable screw mounted for rotation and held against translation by said thrust bearing, said screw being journaled in said housing and having handle means exterior of said housing to rotate said screw; link means connected to said guide pin for movement therewith, a stop collar fixedly connected to said link means, a threaded traveling block mounted for translation along said rotatable screw between said thrust bearing and said stop collar; a bendangle indicator scale fixed adjacent to said traveling block and having indicia thereon, means on said traveling block cooperating with said indicia to indicate the position 7 of said traveling block, and a transparent cover to exclude dirt and protect said indicator scale.

7. An adjustable stop mechanism for a drive means comprising a rod and a traveling block, means for adjustably positioning said traveling block along said rod, a stop collar connected to said drive means and being movable thereby into engagement with said traveling block to prevent further movement of said drive means, an indicator scale disposed adjacent to said traveling block and having indicia thereon, said traveling block having means thereon cooperating with said indicia to indicate the position of said traveling block.

8. An adjustable stop mechanism for a drive means comprising, a rod and a traveling block, means for adjustabtly positioning said traveling block along said rod, a stop collar connected to said drive means and being movable thereby into engagement with said traveling block to prevent further movement of said drive means, an indicator scale disposed adjacent to said traveling block and having indicia thereon, said traveling block having means thereon cooperating with said indicia to indicate the position of said traveling block, and a transparent cover to exclude dirt and protect said indicator scale.

9. An adjustable stop mechanism for a chain drive including a chain and means at one end thereof for pulling said chain, said stop mechanism comprising; a journal block, a screw mounted for rotation and held against translation by said journal bllOCk, a stop collar connected to the other end of said chain and being movable with [respect to said screw, a threaded traveling block mounted for translation along said rotatable screw between said journal block and said stop collar, an indicator scale fixed adjacent to said traveling block and having indicia thereon, and means on said travelling block cooperating with said indicia to indicate the position of said traveling block.

10. Apparatus as defined in claim 9 wherein said stop mechanism is enclosed within a housing, a slot formed in said housing along said screw, said means on said traveling block comprising a pointer, said pointer being disposed in said slot to prevent rotation of said traveling block.

11. An adjustable stop mechanism for a chain drive including a chain and means at one end thereof for pulling said chain, said stop mechanism comprising; a journal block, a screw mounted for rotation and held against translation by said journal block, a stop collar connected to the other end of said chain and being movable with respect to said screw, a threaded traveling block mounted for translation along said rotatable screw between said joumal block and said stop collar, an indicator scale fixed adjacent to said traveling block and having indicia thereon, and means on said traveling block cooperating with said indicia to indicate the position of said traveling block; said stop collar being connected to said other end of said chain by a pair of flat :links and a guide pin, a guide tube enclosing a portion of said chain, slot means in said guide tube, said guide pin being slidably mounted in said slot means to prevent twisting of said chain.

12. In-a tube bending machine, tube bending means including a turnable radius block, means for turning the radius block and including a sprocket and a chain engaged with the sprocket, a single acting hydraulic cylinder and piston means operatively connected with the chain at one end to move the chain in a tube bend effecting direction, a spring means operatively connected at the other end of the chain and effective for returning the chain to its initial position after a bending operation, and adjustable stop means for limiting the movement of the chain in a tube bend etfecting direction thereby to limit the tube bending to .a predetermined angle, said stop means including a stop member adjustable along the path of movement of said other end of the chain, and an abutment member movable with said other end of the chain and engageable with said stop member.

13. In a tube bending machine, tube bending means including a turn-able radius block, means for turning the radius block and including a sprocket and a chain ongaged with the sprocket, a single acting hydraulic cylinder and piston means operatively connected with the chain at one end to move the chain in a tube bend effecting direction, a spring means operatively connected at the other end of the chain and effective for returning the chain to its initial position after a bending operation, and adjustable stop means for limiting the movement of the chain in a .tube bend effecting direction thereby to limit the tube bending to a predetermined angle, said stop means including a captive screw rotatable but held against endwise movement relative to said other end of the chain, a stop member threaded on the screw and adjustable therealong in one direction or the other by rotation of the screw, and an abutment member movable with said other end of the chain and engageable with said stop member in its position of adjustment on the screw.

14. Tube bending means as defined in claim 13 wherein there also is included a tube bend indicating scale, an indicator movable with the stop member and in cooperative relation to the scale.

15. Tube bending means as defined in claim 13 wherein there also is included a tube bend indicating scale, an indicator movable with the stop member and in cooperative relation to the scale, said other chain end, said screw, said stop and said abutment being mounted in a housing and said indicator being operable in a slot at the position of the scale, and there being included a transparent window covering the slot to prevent ingress of foreign matter into the housing and contained lubricant from egress out of the housing.

References Cited by the Examiner UNITED STATES PATENTS 2,312,122 2/1943 Parker et al. 72--149 FOREIGN PATENTS 1,239,404 7/1960 France.

CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner. 

1. IN A TUBE BENDING MACHINE, A RADIUS BLOCK, FLUID MOTOR MEANS FOR ROTATING SAID RADIUS BLOCK, A SPROCKET CONNECTED TO SAID RADIUS BLOCK IN DRIVING CONNECTION THEREWITH A CHAIN ENGAGED WITH SAID SPROCKET, ONE END OF SAID CHAIN BEING CONNECTED TO SAID FLUID MOTOR MEANS AND THE OTHER END OF SAID CHAIN BEING CONNECTED TO AN ADJUSTABLE STOP MECHANISM FOR LIMITING THE MOVEMENT OF SAID CHAIN, SAID STOP MECHANISM INCLUDING A ROD AND A BLOCK, MEANS FOR ADJUSTABLY POSITIONING SAID BLOCK ALONG SAID ROD, A STOP COLLAR CONNECTED TO SAID CHAIN AND BEING MOVABLE THEREBY INTO ENGAGEMENT WITH SAID BLOCK TO PREVENT FURTHER MOVEMENT OF SAID CHAIN. 